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Pernicious Anaemia Society
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Blood test results - advice pls


We have just received the results of a Medichecks health check blood test on my husband. I wanted him to get it done (bear with me it is relevant!) because he had a cholesterol test about a year ago as part of a health check he gets with work and it was a little high. He also does a very stressful job with long hours and a long commute. He has always been quite resilient but has started having trouble sleeping and getting various physical ailments such as gum disease and recession, some Ibs type symptoms, and he is constantly exhausted. We have been putting this down to stress and lack of sleep. He doesn't have any other b12 deficiency symptoms.

Because of all of this I wanted him to get a blood test just to check everything was ok, there wasn't anything else going on/the stress and lack of sleep wasn't impacting his bloods.

Everything came back ok except b12 which was 233.5 (140-724). I know they are related so for completeness his folate is 9.08 (3.89-26.8).

Although in range I know his b12 is on the low side. As he doesn't really have b12 deficiency symptoms was going to just start him on 1000mcg oral b12 (methylcobalamin) with thornes b complex.

Would welcome views on this approach or whether we should be checking anything else.

Many thanks.

25 Replies

Hi MiniMum97 I'm not medically trained but as I understand it your husband's "IBS type symptoms" may put him "at risk" of developing a B12 Deficiency.

Both the B12 and Folate readings are at the bottom end of the scale and if his doctor is not going to give him any treatment perhaps supplementing with both may be the way forward if for no other reason than to see if there is an improvement. Please do however start the B12 before the folic acid for a day or two.

There will be other's on here who will be able to give more qualified advice.


Hi MiniMum

The b12 although not very low is low enough to cause symptoms like fatigue and insomnia however you would need an active b12 to confirm deficiency/ PA. Is your husband a vegetarian/ vegan. Check to see if the blood test has a ferritin result and Vit D, not normally included in CB COUNT.

Has the B12 been tested previously does it show a trend downwards?



No he is not vege/vegan. Ferritin was ok at 127.7 (30-400). Not mid-range but his blood serum iron was slightly over range 33.29 (10.6-28.3) and T IBC 77.99 (41-77) so have assumed supplementation not needed or a good idea. Vit d 83.68 (50-200). Ok I thought as we are Just coming out of winter.

Have put him on 5000iu twice a week as he is

indoors all week and could be slightly higher. Going to retest levels in 4 months to check we are not overdoing anything.

Should we get an active b12 done now? Is it ok to

have started supplementing?

B12 has not been tested before so we can't see if

there has been a trend.

Thank you



Don't supplement if you are getting an active B12 as it will skew results however your gp may not agree to testing active b12 but you can get a finger price test through Blue Horizon medicals by post privately. Then once you have ascertained whether the b12 is due to Malabsorbsion meaning Pernicious Anemia then you will be able to start either tablet or injections. Take a look at the pernicious anemia society website for further support.

Regards Mark


I think my question is does he need further testing given lack of symtoms. My guess would be that his stress and exhaustion are the likely causes for his slightly depleted b12?


We've already started supplementing but only for two days.


If he's not symptomatic and has in range b12 then mega doses are probably a bad idea as potentially it could trigger a functional deficiency.

Why not just add a multivitamin with maybe 20-50 mcg of b12 in and see how things go.

The 1000+ mcg are only needed if you can't absorb b12 efficiently.


Do you have any references that support what you say about high doses of b12 triggering a functional deficiency. I haven't heard this before and can't find anything online? Many thanks.


This is really Gambit62 's baby and here's a previous post on it.

My limited understanding of it is the body responds to very high levels in some people by producing antibodies to b12 to block it at a cell level. Almost like an excess b12 protection mechanism.

I don't believe it happens in many people though. It's quite rare. I've also only ever read about it on here. Everything else I've read would suggest there is little or no risk from high intake. It would seem to make sense and have credibility though when you consider how clever the body is at protecting its self.



please take a look at the pinned posts

this link is particularly relevant


and a reference on functional deficiency



as Steap says dosing with very high dose B12 tablets isn't recommended. Unless you have an absorption problem, at best, it is a waste of money.

low B12 does make you more susceptible to stress and lowers the immune system but so will a lot of other things - including folate deficiency - though the results above aren't indicative of folate deficiency.

People vary a lot in how much B12 they need in serum and how this relates to what is happening at the cell level. Its just one part of B12 metabolism.

Did you have a full blood count - B12 deficiency causes a non-iron anaemia - macrocytosis/megaloblastic anaemia - in which red blood cells are rounder and larger than they should be and some of what you say above about iron is consistent with this - folate deficiency will also cause this anaemia.

There are several forms of B12 and methyl isn't necessarily the best form - despite hype to the contrary.

1 like


I've had a chance to have a look at these now and can't see where it says that high doses of oral B12 could cause a functional deficiency?..although it seems to make reference to intravenous B12 can sometimes "lead to the development of anti-TCB II autoantibodies, which result in a reduction in TCB II clearance".

Am I missing something?



functional deficiency is a response to high levels of B12 in your blood -

it doesn't have to get into your blood as a result of intravenous injections.


I really don't think that paper says that. I can see that it says that functional deficiency can occur at the same time as having high levels of b12 in your blood but this isn't the same as the high levels causing functional deficiency. Have I missed something? Can you point me to where it says it can cause a functional deficiency?

Thank you!

1 like

"Indeed, an increase in the binding of vitamin B12 to HCs, secondary to an elevation in their plasma levels (especially for TCB I and III which are by far the majority), leads to a potential decline in its attachment to TCB II and therefore alters its delivery to the cells."


Doesn't seem to say whether this is temporary or permanent? I tried to check the source document but it's in french!


not sure which of the two documents you are looking at so don't know what the 'source document' you refer to is.


Sorry, looking at the one you quoted above. This references to another study which is in french. Tried to google translate but it's not making much sense. I am concerned as on Thyroid UK forum people with hypothyroidism are being told to get B12 levels up to 1000 by taking 5000mcg lozenges. If there is a risk of this causing functional B12 deficiency people should be aware; however I don't want to start rocking the boat without good/unequivocal evidence, and I am not sure this paper provides this. Have you seen this stated anywhere else?


I quote 2 articles above - are you referring to the first or to the second.

The first article is from a dutch organisation that does a lot of research.

Yes, I know there is a long standing myth that people need to have levels of 1000 or more to be okay on TUK - It is true that people who are bieng treated for B12 absorption problems tend to need higher levels on average and this is probably where the figures come from but they have been quoted out of context and there is certainly no point in supplementing if you don't have any symptoms of B12 deficiency but this is never mentioned on TUK.

Its quite difficult to find good quality info functional B12 deficiency as it isn't something that appears to have been the subject of a lot of research.



You reference two papers, but only quote one, which you have done in bold above. For clarity the quote is: "Indeed, an increase in the binding of vitamin B12 to HCs, secondary to an elevation in their plasma levels (especially for TCB I and III which are by far the majority), leads to a potential decline in its attachment to TCB II and therefore alters its delivery to the cells." This quote seems to say that increased serum B12 can cause a drop in the take up of B12 and therefore make less B12 available to the cells? However it doesn't say whether this is a reversible or permanent effect? It doesn't go into enough detail for me, and annoyingly the paper it references to is in french as this may yield some more information.

Found this on another website but only refers to long-term use of B12 injections:

"Transcobalamin II Antibodies

Hereditary illnesses and long term use of vitamin B12 injections can sometimes lead to the production of antibodies against transcobalamin II, leading to vitamin B12 not being properly used"

I think most of the time people are posting because they do have symptoms. Also people with hypothyroidism are more likely to have problems absorbing vitamins incl B12. Hence the recommendations I expect.

Not sure what to do myself as I have symptoms which could be B12 and could be hypothyroidism such as skin tingling and numbness, but ave stopped supplementing B12 pending this discussion!


excwss B12 will eventually be removed from the blood( filtered out by the kidneys) though TCII antibodies do seem to slow this down from what I have read. The rate at which excess B12 is removed from the blood is greater when the levels are really high - and there is a huge personal variation in gow quickly it is removed -and it can also be different for different firms if B12 ...


Raised cholesterol is a low thyroid symptom. Before thyroid testing in the 70's - anyone with raised cholesterol had their thyroids treated 😊

Thorough testing required and not just the TSH. Also the FT4 & FT3 along with BOTH anti- bodies TPO & Tg.


He had his TSH checked when his cholesterol was checked and it was under 1. He has increased exercise and made a few diet changes and his cholesterol has come down so think this is ok.


Most of the cholesterol is made in the body and very little to do with diet. Cholesterol is needed to make all hormones and needed for the brain - a huge part of which is cholesterol :-) Also needed to make VitD in the body - and it is the LDL that is involved in that process. Hence all those people on Statins now have low VitD and the accompanying illnesses. The new generation of Statins will now contain VitD - I wonder why !


Hi all

Have a few more tests back that the GP has done:

B12 has crept up a bit (although range is different) to 361 (197-771) (Previous test was 233.5 (140-724)). Folate however has dropped a bit, in range but low end - Serum folate level 6 ng/ml [3.9 - 25] (Previous test was 9.08 (3.89-26.8)).

We tested his active B12 also and this was 77.1 pmol/L 25.10 - 165.00.

Think all the tests below are related to anaemia, and they look fine?:

Haemoglobin concentration 14.8 g/dL [13.5 - 18]

Mean cell haemoglobin level 30.1 pg [27 - 32]

Mean cell haemoglobin concentration 33 g/dL [31 - 36]

Mean cell volume 91.3 fL [76 - 100]

Red blood cell count 4.92 10^12/L [4.5 - 6.5]

Haematocrit 0.449 [0.4 - 0.54]

I've noticed that the following is slightly over range:

Serum alanine aminotransferase level 43 iu/L [0 - 41] which seems to something to do with liver function but overall test results says "normal", so not sure why this being slightly over range wasn't commented on (a month ago this was 18.6 IU/L (10.00 - 50.00)).

I have noted that his potassium is also right at the top of the range - Serum potassium level 5 mmol/L [3.5 - 5.1] (A year ago this was 3.9 (3.5 - 5.1


Here are his iron results from a month ago too:

IRON *33.29 umol/L 10.60 - 28.30

T.I.B.C *77.99 umol/L 41.00 - 77.00

TRANSFERRIN SATURATION 42.68 % 20.00 - 55.00

FERRITIN 127.7 ug/L 30.00 - 400.00

Any thoughts?

Thank you!


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